EGG HARBOR, N.J. — Up in the cockpit, Larry Van Hoy, a Federal Aviation
Administration pilot, was flying low-tech. Radar showed a bit of nearby cloud
cover, and to learn about other aircraft, he talked to the ground controller or
looked out the window.

Back in the passenger cabin of the same plane, a Bombardier Global 5000,
Wilson N. Felder, director of the F.A.A.’s William J. Hughes Technical Center,
was flying in the cockpit of the future.

Dr. Felder was watching an Automatic Dependent Surveillance — Broadcast, or
A.D.S.-B., display that uses the Global Positioning System for navigation. The
display gave him an overview of the terrain below with airports labeled. He
could tune in weather at any altitude. A ground-based data feed sent him a
constantly updated picture of the other aircraft sharing the sky. These appeared
on the display screen as green crescents.

The screen also showed two green spearheads. These, Dr. Felder said, were the
nearby aircraft that were also equipped with the new technology. They sent their
positions directly to the Global 5000.

A.D.S.-B. is a linchpin of the Next Generation Air Transportation System, or
NextGen, the aviation agency’s master plan for fixing the shortcomings of
21st-century air travel.

The United States air traffic system normally handles about 50,000 flights
per day, and in the first half of 2008, more than 25 percent were either late or
canceled. The scorecard improved slightly after the economy collapsed — flights
are currently down to 47,500 per day — but by 2025 the F.A.A. predicts daily air
traffic will be up to 80,000 flights. The current system is struggling badly. By
2025, it will not have a prayer.

There are many reasons for this mess. Radar is rapidly becoming a dinosaur —
too slow for modern times. Air traffic controllers see a new ping from the
planes on their scopes every six or seven seconds, and air traffic radars “see”
for only about 150 miles. When aircraft are crossing the Gulf of Mexico on the
same compass heading, they leave airports 10 minutes apart because each must be
surrounded by 100 square miles of “sanitized” space to avoid accidents. This
curtails service.

Over busy airports, planes often circle in altitude “layers,” speeding up and
slowing down to get into proper landing sequence. This wastes fuel. To land,
they depend on controllers who are talking to every plane in a stream of nonstop
oral radio transmissions. In the tower, controllers keep track of vital details
by means of plastic “flight strips” that look like tile racks in a Scrabble
game. A ground controller hands the strip to a local controller, who gets the
plane in the air and passes the strip to another controller. The controllers
have to keep everything straight on their radar screens, in their minds and on
the radio. Theirs is one of the most stressful jobs around.

NextGen is supposed to fix all this. By 2025, all aircraft will be using
GPS-based technology for navigation, and radar will be a backup. New
technologies, like A.D.S.-B., will deliver fixes every second, and aircrews will
monitor their progress on digital cockpit displays like the one Dr. Felder was
using.

Electronics will give controllers recommended changes in altitude, course and
trajectory to ensure the most efficient and smoothest ride possible. And when a
plane reaches the airport, it will use precision navigation, even in bad
weather, to come straight in, like a jewel on a string of beads. The controllers
will be there, but they will not be talking constantly — only when pilots need
help.

Victoria Cox, the F.A.A.’s senior vice president for NextGen and operations
planning, described the system as a “supermodern concept of aviation.”

But in the computer age, many may wonder why changes like these have not been
in place for years. After all, motorists already use GPS devices to find their
relatives in the suburbs, weekend sailors use them to fish for blues off Cape
Cod and aircraft have had access to GPS for years. Pilots in the United States
can already use what is known as the Wide Area Augmentation System, which offers
enhanced GPS so they can fix their location more precisely.

NextGen is different. Wide Area Augmentation “gives more accurate information
to let you know where you are,” said Michael Romanowski, the F.A.A.’s director
of NextGen integration and implementation.

NextGen’s progress has been rocky. Since its beginning in 2004, lawmakers and
civil aviation experts have complained of its vagueness and the absence of a
concrete plan. Also, the Government Accountability Office regarded the F.A.A.’s
procurement strategy generally as inefficient and “high risk,” raising fears
that the agency would never be able to see the program through to a finish.

This year appears somewhat smoother. The F.A.A. is off high risk for the
first time in a decade, and in January it issued a plan that described how the
NextGen air traffic system would look at “midterm” in 2018 on its way to
completion.

The F.A.A. has asked the civil aviation industry to come up with a method of
rewarding the forward-looking. Ms. Cox said companies that were the “best
equipped” early innovators should be the “best served” at airports and during
flights. At the same time, however, laggards must be accommodated for some
years. As a result, the two systems, old and new, will have to co-exist until
NextGen builds enough momentum to eclipse yesterday.

Many of NextGen’s needed technologies are being developed at the F.A.A.’s
technical center, a 5,000-acre stretch of runways, labs and grassland in the
South Jersey flats near Atlantic City. On one summer afternoon, engineers were
testing NextGen air control techniques at a virtual Newark Liberty International
Airport, while F.A.A. experts a few doors away fine-tuned a futuristic
electronic depiction of the runways at Logan International Airport in
Boston.

A.D.S.-B. figures to be a core NextGen technology, integrated with other
GPS-linked systems that will let aircraft not only fly more efficient routes,
but also pick up continuous digital data feeds for updated weather and traffic
information.

In the future, NextGen will provide a “data cube” that taps weather sources
all over the country and delivers data that will tell aircraft and controllers
what lies ahead for any flight in all three spatial dimensions and time.

Governments will cover the nation with GPS-linked ground stations about half
the size of a standing refrigerator. As the technology improves, aircraft will
find it easier to land in bad weather, and at some point, the electronics will
be able to place them on a safe track and bring them in quickly on several
runways at the same time. Airports must have the technologies ready when
aircraft are ready to use them.

There appears to be little doubt that the new technology works. Unlike radar,
with its immense installations costing millions of dollars, the A.D.S.-B. ground
stations can be mounted anywhere.

As proof of concept, the F.A.A. distributed enough of them to cover Alaska.
The accident rate in the state — extremely high because of vast, radar-free
areas and wretched weather — dropped 47 percent for the small commercial
aircraft that were outfitted with onboard A.D.S.-B.

In the Gulf of Mexico, the agency is mounting A.D.S.-B. ground stations on
some of the gulf’s 9,000 gas and oil rigs, giving the helicopters that supply
them a way to travel to and from the coast in reasonably bad weather without
getting laid low by a derrick. The F.A.A. expects the system to begin operations
next month.